private void InitializeTextureUnits()
{
// Bind a dummy texture to all texture units
byte[] whiteData = new byte[4];
whiteData[0] = 255;
whiteData[1] = 255;
whiteData[2] = 255;
whiteData[3] = 255;
dummyTexture = new TextureGL(1, 1, PixelFormat.Rgba, PixelInternalFormat.Rgba);
dummyTexture.Upload(whiteData, 0);
nearestSampler = new SamplerGL1();
nearestSampler.MinFilter = TextureMinFilter.Nearest;
nearestSampler.MagFilter = TextureMagFilter.Nearest;
nearestSampler.Wrap = TextureWrapMode.ClampToEdge;
int textureUnits = 4;
try
{
GL.GetInteger(GetPName.MaxTextureUnits, out textureUnits);
}
catch (Exception)
{
}
for (int i = 0; i < textureUnits; ++i)
{
try
{
GL.ActiveTexture(TextureUnit.Texture0 + i);
dummyTexture.Apply();
nearestSampler.Apply(i, TextureTarget.Texture2D);
}
catch (Exception)
{
}
}
float[] zeros = { 0.0f, 0.0f, 0.0f, 0.0f };
for (int i = 0; i < 8; ++i)
{
GL.Light(LightName.Light0 + i, LightParameter.Ambient, zeros);
}
}
// \brief Find a sampler based on key and set it to use the specified texture
// \note This does not change any Program state; Programs are assumed to be already associated with samplers
public void SetTexture(string key, TextureGL texture)
{
var samplerUniform = Samplers.Global.Sampler(key);
if (samplerUniform == null)
{
return;
}
int textureUnitIndex = samplerUniform.TextureUnitIndex;
if (textureUnitIndex == -1)
{
return;
}
GL.ActiveTexture(TextureUnit.Texture0 + textureUnitIndex);
texture.Apply();
samplerUniform.Sampler.Apply(textureUnitIndex, texture.BindTarget);
// \todo cache textures? textures[key] = texture;
}